Electric flasher



Dec. 4, 1928.

J. W. PHELPS ELECTRIC FLASHER Filed Feb. 17, 1926 Patented Dec. 4, 1928.

UNITED STATES JAMES W. PHELPS, OF CHICAGO, ILLINOIS.

ELECTRIC rLAs'HEn.

Application filed February 17, 1926. Serial No. 88,969.

My invention relates to improvements in an electric circuit make andbreak device and has special reference to a simple flasher for use in asmall capacity circuit, such as a string of small incandescent lamps fordecorative use such as is commonly used on Christmas trees. In such astring, or series ot' small decorative lamps, the lamps are connected inseries, usually eight being used on a string l0 and collectively havinga resistance sufficient for use on a 110 volt circuit.

To cause the lamps of such a. string to. flash it is only necessary tounscrew any one of the eight lamps, screw one of' my flashers in thcsocket and then screw the lamp into the outer end of the device. Forthis purpose the flasher is wound in series with the lamp and when thecircuit is alternately made and broken it causes all of the lamps ol theseries to flash in unison. By the use ol several strings,

each having its own flasher in circuit, a most beautiful kaleidoscopiceffect can be produced and at a relatively small cost.

The object of my invention is to provide such a device of such simpleform and construction t-hat it can be manufactured and sold for thepurpose mentioned and at a price which shall be commercially successful.

My invention will be more readily understood by reference to theaccompanying drawings in which Fin'. 1, is a diagrammatic viewillust-rat ing the application of 1n invention to a string of smalldecorative amps;

Fig. 2, is an enlarged longitudinal, central, sectional view of aflasher made in accordance with my invention on the line 2 2 of' Figs. 3and 4;

Fig. 3, is a similar sectional view on the line 3`3 of Figs. 2 and 4;

n -Fig. 4, is a transverse section on the line 4-4 of F ig. 2; i

y Fig. 5, is a view similar to Fig. 2 and showing a slight modificationin construction and taken on the line 5-5 of Fig. 6; and

Fig. 6, is a transverse section on the line 6--6 of Fig. 5.

In said drawings 1 illustrates a string of small decorative lamps 2 suchas is commonly used on Christmas trees, and 3 illustrates one of mysmall or midget flashers screwed into one ofthe small sockets 4 and thelamp screwed into theouter end of the flasher.

My improved small or midget flasher comprises a metallic tubular shell 5formed into a screw socket 6 at one end for receiving one of the lamps 2and formed at the other end into a screw plug 7 for screwing intothesmall sockets 4. This shell forms one side ot' the electric circuitfor carrying the electric current.

For forming the central contacts for the plug 7 at one end and thesocket 6 at the other end I provide a central member 8 of insulatingmaterial such as fibre, hard rubber, porcelain` or the like and whichhas at tached thereto the central contacts and the make and b-reakdevice or mechanism. This member 8 is a flat strip and long enough tocXtend from the outer end of the plug 7 to the base of the socket 6. Themember 8 substantially fits edgewise within the tubular casing 5 and isadapted to be entered into the `casing through the socket end of1 same.The

member Smay be held in the c-asing 5 by any suitable means such as a pin9 entering through the casing 5 and into the edge of the member 8. Oneend 10 of the member 8 is shouldered. The member 8 is about onefourth ofthe diameter ofthe shell 5, in thickness, for the purpose of providingspace at the sides of the member 8 for the vcontacts and flashingdevice.

At the plug'end of the device the center contact 13 is formed of a thinstrip of sheet metal 14 secured to the member 8 by any suitable meanssuch as the rivet 15 and bent over at its outer end slightly beyond theend of the member 8 to form the contact 13 so that it will be slightlyyielding. At the opposite end the central contact 16 is formed by asimilar stri of sheet metal 17 secured rigidly to the mem er 8 by anysuitable means such as the rivet 18 and formed with its inner end 19bent back upon itself to receive an adjusting screw 20, the strip 18being provided with suitable threaded openings for this purpose.

Upon the side of the member 8 opposite to the end 17 of the strip 16, Imount a very simple thermostatic make andmbreak element 21. This elementconsists of a strip 22 of bimetallic sheet metal covered bya sheet ofinsulation material 23 and upon which is wound a current carrying wire24 adapted to be heated when current passes through the device and causethe alternate making and breaking of the circuit. r1`he element 21 isrigidly mounted on the member 8 adjacent to the plug end of the device,as by rivets 25, and the element is formed so that its body and oppositeend 26 stand clear of the member 8. The free end 26 of the element 21 isprovided with a contact 27 adjacent to the free end of the screw 2O andadapted normally to rest upon same and close the circuit preparatory tothe initiation of the make and break action upon the beginning of a flowof current through the device. To complete the circuit through thedevice one end 28 of the wire 24 is connected to the strip 14 formingthe center contact 13 and the opposite end 29 is soldered to the freeend of the bimetallic strip 22. The tree end of the strip 17 which isbent over to form the center contact 16, is normally formed out ofcontact with the adjacent end of the member' 8 to make it slightlyyielding.

Preferably the tubular shell is encased within a tubular casing 30 ofinsulation material such as fibre or the like` and which extends fromthe outer end of the socket`6 to the base of the plug 7. The adjustingscrew 2O projects through a free opening 31 in the tubular shell 5 andthe outer casing 30 is provided with a hole in which the screw 20substantially tits and which construction practically dowels or securesthe outer casing 30 upon tubular shell 5. By means ot the adjustingscrew 20 the frequency of the make and break action can obviously beadjusted or changed.

For some uses it is not desirable to permit any adjustment of the makeand break device after it has been completed, and for this purpose theform of device shown in Figs. 5 and G is provided. In this form theadjusting screw is eliminated, and instead of the contact strip A17forming the center contact 16 being arranged on the opposite side of themember, 8 from the thermo element 21, it is arranged on the same sidewhere it can contact directly with the free end oi the thermo elementand thus complete the electric circuit. In this form, in order to retainthe insulating casing 30 in place, it is secured by means oi' a dowelingpin 32 which passes through the two shells and into the member 8, thusnot only doweling the two shells together but also securing the member 8against move ment in the metallic tubular shell 5.

It will be seen that my improved make and break device is very simple inconstruction, that the make and break device comprising the member 8 andits attached contacts, including the thermo element, can be completed asa unit and then entered into the shell 5, that the several parts of thedevice can be easily and quickly assembled and be held permanently inplace and that the whole can be constructed or produced at a relativelysmall cost.

As many modifications of my invention will readily suggest themselves toone skilled in the art, I do not'limit or confine my invention to thespeciic details of construction herein shown and described.

I claim:

A device of the kind described, comprising a metallic tubular shellformed into a socket at one end and a plug at the other, a flat bar ofinsulation material fixed within the shell and extending centrallythrough the shell from the outer end of the plug to the base of thesocket and presenting' spaces on each side of the flat bar, bendablecenter contacts for the plug and socket carried by the bar andprojecting out from the ends thereof, and a thermostatic make and breakelement carried by the bar normally in contact with the center contactat one end and permanently connected with the center contact at theopposite end and adapted to intermittently make and break said normalcontact.

In testimony whereof, I have hereunto set Umy hand, this 11th day ofFebruary, 1926.

JAMES IV. PHELPS.

